1. Technical Field
The present invention relates to a curable resin composition, an infrared ray cutoff filter and a solid-state imaging device using the same.
2. Background Art
A CCD or CMOS image sensor, which is a solid-state imaging device for a color image, is used in, for example, a video camera, a digital still camera, or a mobile phone mounted with a camera function. Such a solid-state imaging device employs a silicon photodiode in its light receiving portion, the silicon photodiode having a sensitivity to near infrared rays. Thus, the solid-state imaging device is required to perform a visibility correction, and thus employs an infrared ray cutoff filter (see, e.g., Japanese Patent Application Laid-Open No. 2012-28620).
As for such an infrared ray cutoff filter, a dielectric multilayer film-using type filter, and an infrared absorbing agent-using type filter are known.
As for the dielectric multilayer film-using type infrared ray cutoff filter, for example, an infrared ray cutoff filter using a blue glass substrate as a base material is known.
Also, as for the infrared absorbing agent-using type filter, an infrared ray cutoff filter of which most of constituent materials are made of glass is mainly known.
For example, Japanese Patent Application Laid-Open No. 2012-185385 discloses a near infrared ray absorbing filter which employs a specific copper complex.
The dielectric multilayer film described above is known to have an infrared reflectivity, and has conventionally been formed by vapor deposition. However, the vapor deposition requires a high temperature of, for example, 250° C. For example, when in manufacturing a solid-state imaging device, a dielectric multilayer film is formed on a substrate having a color filter layer, there has been a problem in that a color filter layer may be denatured or degraded by vapor deposition. Therefore, it has been studied to form a functional layer having an infrared reflectivity without depending on vapor deposition.
Also, a blue glass substrate used in the above described dielectric multilayer film-using type infrared ray cutoff filter is known to have a near infrared ray absorbing ability.
However, the blue glass substrate is fragile, and for example, when an infrared ray cutoff filter employing the blue glass substrate is used in manufacturing the solid-state imaging device, there has been a problem such as degradation of production suitability in that, for example, dicing cannot be performed.
Therefore, it has been studied to develop an infrared ray cutoff filter having an infrared reflective film not formed by vapor deposition, which does not use a blue glass substrate, but has a near infrared ray and infrared ray shielding property equal to or greater than a case where the blue glass substrate is used.
Also, when the surface of a substrate of a solid-state imaging device is opposite to an infrared ray cutoff filter across a space, incident angle dependence of light received by the solid-state imaging device may be increased, thereby causing a problem of color shading.
An object of the present invention is to provide a curable resin composition capable of forming an infrared ray cutoff filter which has a near infrared light shielding property, and an infrared light shielding property without vapor deposition, and the infrared ray cutoff filter obtained therefrom.
Also, by using the curable resin composition, the infrared ray cutoff filter, and the surface of the substrate in the solid-state imaging device may be brought into close contact with each other with no intervening space, and thus an object of the present invention is to provide a solid-state imaging device with a suppressed color-shading.